The present invention relates to a plasma production apparatus (plasma source) using microwave power as an excitation source. For example, the present invention relates to a microwave plasma production apparatus which can be used as an emission source or a particle (ion, radical etc.) source in etching, deposition, surface treatment, surface modification and trace element analysis of a material, or as a high-brightness short-wave light source of optical reaction.
Conventional plasma production means using power of microwave (1 GHz or higher) are discussed in (1) Rev Sci. Instrum., 36, 3 (1965), pp. 294 to 298, (2) IEEE Trans. of Elect. Plasma Sci., PS-3, 2 (1975), pp. 55 to 59, and (3) Rev. Sci. Instrum., 39, 11 (1968), pp. 295 to 297, for example.
On the other hand, plasma production means using RF power of several hundred MHz or lower are discussed in (4) Philips Tech. Rev., 23, 2 (1973) pp. 50 to 59, for example.
In the prior art using microwave power as described in aforementioned literatures (1), (2) and (3), the structure is complex, and dimensions are limited. No attention is paid to improvement of utilizing efficiency of microwave power, realization of large-diameter and high-density plasma, optimization of radial distribution of plasma, and increase of exciting microwave power. There are problems in physical quantity (such as density) of plasma and its production efficiency, characteristics and throughput of film material obtained when plasma is used for deposition, and sensitivity and cost in an analyzing apparatus obtained when plasma is used for trace element analysis.
On the other hand, the prior art using RF power as described in the aforementioned literature (4) has a complex constitution of an oscillator. There are thus problems in utilizing efficiency of RF power, electric wave obstacle countermeasure and cost.